Folders are used in many document production and handling applications, such as in mail finishing systems, for example. In those applications it is necessary for the folders to fold collations containing a variable number of documents and, therefore, having variable thicknesses.
Conventional folder systems utilize rollers arranged at fixed distances, creating nips having fixed sizes. Those nips are generally configured to process collations of a given size. In some arrangements, in order for the folder to process larger collations, manual adjustment of the rollers is required. The adjustment process is very time consuming and, once the rollers are adjusted for larger collations, the folder is unable to process smaller collations. This adjustment process may require a service technician to set the roller gaps by removing covers and brackets, loosening the drive chain, loosening the fasteners that hold the rollers fixed, and using gage blocks to set the correct gap. The complexity of the procedure makes it very difficult for a typical operator to perform without special technician training.
In other arrangements, passive, spring-biased rollers are used to adjust the roller spacing to accommodate collations having varied thicknesses. Such systems allow the processing of collations within a given thickness range, but lead to excessive force and noise when race sing thicker collations. In addition, such systems often destroy the documents of the collation by leaving visible marks on the documents from the rollers.